Telephone system.



B. E. CLEMENT. TELEPHONE SYSTEM.

AEPLIGATION FILED MAR. 30, 1906.

1,107,144. Patented Aug.11,1914.

' 3 SHEETS-SHEET 1.

Witneooea 4 E. B. CLEMENT.

TELEPHONE SYSTEM.

' APPLIUATION FILED MAR. so, 1906.

E, B CLEMENT.

EPHONE SYSTEM.

ATION FILED MAR.30, 1906.

TEL

APPLIO Patented Aug. 11, 19%

3 SHEETSSHEET 3.

pwentoz ED'XVARD CLEMENT, 0F WASHINGTQ'N, DISfEICT OF Ct Bin, \ASSIGNOR, BY

MESNE ASSIGNMENTS, T0 FREDERICK C. STEVENS, OF A'LTEGA, H3333 YORK.

snrnrnonn si'srnni.

LlQli i l.

Specification of Letters Patent.

Patented Aug. 11, lilies.

Application. filed "March 30, 1906. Serial No. 309,010.

To all whom it may concern Be it known that l, Enwann E. CLEMENT, a citizen of the llnitcd States, residing at lVashin ton, Dist ict of Jolumbia, have invented certain new and useful Improvements in Telephone Systems, 03": which the following is a specification, reference being had therein to the accompanying drawing.

Myj invention relates to telephone exchange systems, and particularly to those in which a combination of manual and automatic devices is employed for the purpose of interconnecting subscribers. Briefly stated, the system of my present invention each switch is carried to multiple-jacks l0- cated in front of the several operators. Each operator is provided with a number of pairs of connecting plugs and cords and with signal controlling devices whereby the automatic connector switches may be controlled. I

In operation, a subscriber calls and'thereby sets a signal in front of the operator, who plugs in with her answering-plug and connects her telephone to the cord by means of an automatic listening key or listening relay as shown, and ascertains the number of the subscriber wanted. Having ascertained this number, she inserts the companion plug into a trunk-jack connected to a connector switch containing the terminals of the desired line. She then sets up on her transmitting device associated with that pair of plugs the number of the line in the connector group, together with the number of the station on the line, it it be a partyline. She then turns to other work, and

pays no further attention to the connection until at the close of the conversation, her disconne t or clearing-out signal is exhib ited, when she pulls down the plugs; When the operator has set up the sending device,

which preferably consists of a set of pushbutton keys bearing the numbers to which they correspond, she connects the cordon. cuit thereby to a common power-driven com-- mutating device, by which the-desired selecting impulses are placed upon the trunk in proper sequence. The switch lpreier to employ is a two-motion spindle switch havmg its contacts either in vertical rows or lation, thatis to say one hundred contacts in ten sub-divisions of ten contacts each. T he arrangements and circuits of this switch will not be made the subjects of claims in the present case. The only mechanical movements in the switch are the two movements of its spindle to select the contacts of the line Watend; all the various changes required being produced by relays In order to select an idle trunk, the operator tests the multiple-jacks of the particular hundred desired, preferably by sliding her plug tip along the row, as usual in similar tests at present. By this huge-merit l only to select two digits 1 any switch, in order to find a line wanted, xample, suppose the number called for is The 4': (3S. operator tests and plugs into idle trunkjackin the group numbered l and sets up the buttons of the signal sender tor the number 68. She sets also an additional button to determine the station required upon the line indicated. I provide relays which respond to the party-linc impulses to apply the proper generator connections to the line, and I also provide an automatic controlling device which rings the subscriber at the proper intervals, until he answers. lVhen the subscriber answers, the generator is cut off and the talking circuit established.

In the system I have illustrated and shall describe in connection herewith, I employ a common battery at the central oflicc, and what is known as harmonic ringing. It will be understood, however, thatct-her systems and other circuits may be. employed without departing from the spirit of my invention.

ll1e'invention is illustrated in the accompanying drawings, in which tery outfit, consistin of transmitter, rc-

hori'zontal rows, and arranged in decimal re- Figure 1 is a diagram of a subscribers stahaving the usual subscriberscommon batrelay, R

ceiver, switch hook, ringer and condenser. From this substation the'line-wires 1-2 extend to the central office, where they pass through the contacts of the cut-oil? relay, M, which normally connects them to the linerelay M and ground, respectively. The line relay is connected on the other'side to the main battery, B, and controls a signal lamp, L associated with the answering-jack, J. The answering-jacks, J, are supposed to be grouped in a convenient manner, with their signal lamps, operators, and when any lineis calling it is intendedthat it shall be connected through a trunk-jack, J, with a trunk-line leading to an automatic switch, )8, (see Fig. 3), by which the subscriber Wanted can be directly reached. v

In order to interconnect the line and trunk-jacks I provide a pair of plugs, P, P, having their tipsand sleeves respectively connected through the conductors 35 and 4-6, these conductors being interrupted for direct currents by the condensers, C. .The answering plug, P, has associated with it a supervisory signaling lamp, L, directlycontrolled by the tip relay, R, which responds to current in the subscribers line as long as the plug is inwav jack; the lamp is also indirectly control' ed by the sleeve relay, R, which puts battery on the armature of the tip relay when the plug is first inserted, Current through the sleeve relay is also necessary in order to energize the cut-off relay,

M, of the line in making connection therewith. The calling plug, P, has three contacts, which I may call the tip, ,0, the ring, 9, and the sleeve, 39 the ring in this case corresponding to the sleeve of the plug, P. When the plug is inserted in a trunk-jack, J, the tip and ring come into connection respectively with the jack springs, j, 7', while the sleeve, p comes into contact with a thimble, 7' connected through a resistance, j, to ground. This thimble is for test and also to furnish a circuit for the cord cut off There are two-relays, R R associated together for controlling the connection of the operators telephone. The relay, R', takes current through the wires 17 and 18 when the plug, P, is first inserted in answer to a call, the circuitB, 19, 17, 18 and ground being then immediately closed by the relay, R, pulling up. Thereupon the relay, R immediately pulls up, the relay, R", which also controls it remaining quiescent. In so pulling up it closes the two sides of the operators secondary circuit 9----10- onto the bridge wires 78 across thecord-conductors 3-4. This secondary circuit contains the operators receiver T, and the secondary winding, 1', of the induction coil, 1, The primary, 6 included in a shorheircuit 13514: with the cond nser, C, and the transmitter, T, the latter derivtogethcr L, in front of the 'erator can reach any trunk.

ing its current supply direct from the main battery through the choke-coil, 2' by the circuit B,20,2l, 22 and round. The tertiary winding, 7?, is incluc ed in the test circuit l112, which passes from ground through a back contact on the relay, R to the tip conductor5 and so to the tip of the calling plug, P.

The trunk-lincs 23, 24 which terminate in the jacks,

J ,are each multiplied to all the sections of the switchboard, so that any op- The trunks are arranged in groups, those of each group leading to similar switches in which the same group of subscribers line-wires are multiplied.- This is-necessary so as to al- .ways have enough idle trunks and switches to reach a number of subscribers of the same group at the same time. Each connector switch is supposed to contain the terminals of one hundred lines, and as a fair average I may assign ten switches to each one hundred lines, so as to be able to call ten subscribers out of that particular hundred at the same time. All of these subscribers lines are multiplied into the ten switches, and the ten trunks from the ten switches are carried together to the switchboard, where they are multiplied and have their jacks appear together in a group on all the switchboard sections. These jacks may be arranged in a continuous line either tally, so that in testing to find an idle trunk, the operator will simplyrun the tip of her plug down the row in the group desired.

These groups are numbered from O to 99,

which means that through the trunks of N o.

0 group the subscribers lines whose numbers are from 0 to 99 can be reached; through No. 1 grou p those whose numbers are from- 100 to 199 can be reached; through-No. 2 group those Whose numbers are from 200 to 299 can be reached, and so on up to 9999, or if it be desired to carry it-so far, even to 99,999, which would of course require 10,000 multiple jacks per section of three operators positions, which is the same as in a ten thousand multiple-board now. In other words, the same multiple-board which now serves 10,000 subscribers can be cut over by my present invention to 100,000 subscribers, the multiples. In actually reconstructing such a board, it would be necessary to increase the number of answering-jacks and also of cords and plugs since the operators will handle a great many more calls than before. g

In answering a call and making the connection the operator proceeds as follows: Seeing the lamp, L, light, she inserts plug, P, into the corresponding jack, J, whereupon the battery, B, sends current at once through the sleeve relay, R, and the cord-. conductor ,4 to theline-extension 25, to the vertically or horizonaccommodate at least so far as regards cut-oil relay M. and ground.

The cut-off relay thereupon pulls up, putting the line wires l2- onto their extensions 26 and and thence onto the cord-conductors 3 and 4,

whereupon relay R pulls up and opens the conductor leading to the lamp L which had just been closed by the relay R, the entire action being too quick for the lamp to have time to light. At the same time, relay R pulls up and the operators set, 0, is bridged across the answering cord, while the test wire 1112 remains connected to the tip of the calling plug. The operator picks up the plug 1 and at the same time asks Nuin 1?, this producing a click in the receiver, T,

each time the tip, 7), passes over a charged or'busy thimble. Having reached a jack which produces no click, the operator puts in the plug, 1". Relay R pulls up,the.operators telephone is disconnected and the test circuit of that plug is broken.

This much of the operation is substantially the same in any manual system, substituting trunk-jacks for line-multiydes, of course. The balance of the operation. however, is entirely different. The trunk 23-2l shown in the diagram, leads to the connector switch, S,'shown in'l ig. 3, and this switch is operated by means of impulses over the. two sides of the trunk, in a manner which is generally familiar to those acquainted with the art. In order to do this I provide the operators with impulse transmitters or senders These devices 1 term multiple signal senders. The term multiple applies first because the device has the power to produce and send simultaneously a plurality of series of signal impulses; and

second because in each cycle of operation or" the device these series of impulses are each produced a pluralitv of times. It will be obvious from the following disclosure of the operation of this device that in each cycle ofthe multiple signal sender the conditions of proper electrical potential for a plurality of simultaneous series 0'? inn ulses and for the repetition of each ol these seri s of impulses are produced upon the h-adng out wires or bus wires, whence hy the proper provisionof path for current through an p lllllly signal selecting means, current in)- pulses may be taken corresponding to any one of the series of potential impulses of the signal ender, or corresponding to a plulttl'lt o such series. For convenience 1 will first describe this a rangement it is shown 30 and 31, in a manner which will appear from the statement of operation. The wheels, Q, Q Q Qf, eta, numberwheels, the first one having one tootli,-tl1e second two'teeth and so on up to ten teeth.

(For simplicity of illustration only live wheels areshown). i gound these wheels are three sets of pens, connected to the three sets 01 keys, K, Kill. As the wheels revolve from the position in which they are shown in the figure, they make contact with the upper pens, then with the pens, 9 then with those, 9 'lhus the various control circuits governed by the keys and including the wheel contacts are independentl y and differently electrically characterized. The first set ith their buttons or keys, K, transmit the tens digit of any number, the next set transmit the units digit, and the third set transmit the ringing number. All this will appear more clearly from the statement of operation.

The keys, K, K K are 01" the so-called self-latching selective ringing type now in common use on mamial switchbeards,and employ the principle shown in the patent to Ham, No. 6050!)? granted, June 7, 1898. When any key is pressed down it pushes back the latch and releases the one that was previously down, then latching itself. It will be noted that the bank of keys is divided into three sets or rows, K K and K respectively. The rows are each provided with the latching device of Ham, cited, the rows being independent of each other in this respect; thus one key and only one of each row will remain depressed, the, previously depressed keyof each row being released by the depression of any other. In a bank or row of keys of this nature, a key is depressed through a travel. carrying it beyond the locking point: upon release it returns a very short d tance and remains lucked there until released. by the depression of the next key used. 1 take advantage of this detail in the row of k K in. the following manner; The pairs of springs as [42* are to remain locked when the key is pressed, as descrilmd later; but the triple At the same time the pin, 1 of the wheel,

springs Z0 are springs requiring but amomentary contact to energize primarily the pair of locking relays R B. To secure the desired end, 1 so gage the relation of the springs 72 to the push button of "the key that they are closed by the button when at its point of farthest travel but are released by the slight return. travel of'the button before it is locked. The springs however remain closed untilthe button is unlocked and fully released. Each set of keys has a common wire, this for the sets K, K being marked '32, these two being joined together and carried to a back contact of the relay R while that for the set, K is marked 33 and carried to another back contact of the same relay. The numbers to be sent are set up by depressing the keys, one of each row, the key of row K being depressed last, and the act of depressing that key serving to energize and lock therelays R R and then the signal is started at the beginning of a rotation of'the shaft, when the 'first tooth of each wheel is about to strike its pen, 9, by the relay, R being ,deenergized, while the realy, R remains energized. The means of this is in the arrangement of the spring pens, Q5, Q6, on the wheel, Q. This wheel is rotated with the others in the direction of the arrow, and its insulating spot passes first under the spring pen, Q5, momentarily cuttingground off of that and the wire 31, then subsequently under the pen, 9, taking ground oifof that.

In calling the nu mber wanted, which we will assumeto be 4432-3, the operator plugs into a jack of No. 44 group, then presses down button No. 3 of the set, K; No. 2 of the set, K and No. 3 of the set, K The buttons of the sets, K. and K have their several individual wires connected to the springs or pens If, on the several individual wheels, Q, Q etc., and'the effect of pressing down the buttons as'mentioncd is to connect the pen I of the wheel Q through the springs 7.: of the button Z: to the wire 32.

Q}, is wamected through, the springs, 711 of the button Z to the wire and the spring, of wheel, Q, is connected through the springs, Zr of the button, k, to the wire 32. The set of'buttons, K, also have the starting springs, 70. This set of buttons being the last, or ringing set, the number is ready for transmission when any one of them is depressed, hence any one of these buttons not only finishes setting up the number, but by closing the springs, Z2, puts ground. momentarily on the starting wires 37 and 38, which pass to the two relays, R5, R respec-,, tively, and thence through the common return wire39 to battery B and ground. Both the relays pull up, and both lock, the locking circuit of the relay, R being as'follows: B,

39. R r 30, g, Qand ground. The-lock ing circuit of R is as follows: B, 39, R W, 31, 9 Q and ground.

Having thus set up the signal and putit in condition to be started atthe beginning of a revolution ofthe main shaft, and having also plugged into the necessary hundreds group, the operators work'is finished. She pays no further attention to the connection until the subscribers have completed their conversation and have hung up, where upon the relay, R, in Fig. l lets go, and the lamp, L lights to call for disconnection. The operator then pulls the plugs.

The signal having been set up as described, the apparatus of Fig. 2 then operates as follows: The wheel, Q, in revolving will bring the insulating spot under the pen, 9 at first, and might-thereby cut off the relay, R, prematurely, but this is provided for by making a branch locking circuit-310 which is controlled through a contact of the armature, r, and a ground wire 36 of the start ing relay R Hence, as long as the relay, R is energized, the relay, R cannot, be afiected. Moreover, it will be observed-"that the wires 32 and 33 remain disconnected from the wires 151(3 until the relay R is encrgized, while the relay, R is de'elnergized. This condition is brought about when the in sulating spot reaches the pen, 9. The relay R, then lets go, and we have a continuous circuit from wire 32 as follows: 32, 1*, 34, r, 16, 5 (in Fig. 1), and .to trunk-wire We also have a circuit for wire 33 follows: 33, 7 35,1"*, 15, 6 (Fig. l) and the other trunk-wire 24. The insulating spot reaches the pen, 9, just before the first tooth on each wheel reaches its pen, hence as soon as the above desired condition is at-. tained, the set of impulses which has been determined by the key, 70, of the set, K, comes from battery through wheel Q and wire 29 through commutator and key and thence over'the wire 32 to the wire 16 and so on to the wire 23 of the trunk, through which it passes into Fig. 3 to the relay 1%, which will be presently described, and which I shall call for convenience the vertical relay. At the end of this group of impulses, the teeth on the wheels will have gotten around to the pens, Q2, and so the next group of impulses determined by the key, 71: will pass from ground through the wheel Q" and wire 29 througl'i commutator and key and thence onto the wire 33 and so to the wire 1 and the trunk-wire. 24,, through which they reach the relay, R in Fig. 3, which will also be presently described and which I shall for convenience call the rotary re ay. The names of these two relays are quite eurate in this systen'i, because the relay does really produce a vertical motion of the switch S, while the relay It produces a rotary motion thereof. At the endof this second group of impulses, the teeth on the no ice wheels nave gotten around to the th 'd set of pens, 1 and the impulses determined by the hey. if, then come from battery through wheel Q" and wire through commutator and key and thence through the wire 32 onto the wire 16 and so again to the trunkwirc and to the vertical relay, l. After this, the insulating spot on the wheel, 9., reaches the spring, giand momentarily cuts oil the ground therefrom. Since the relay, R is already deenergized, this breaks the locking circuit of the relay, R and it lets go, disconnecting the wires l516 from the wires 34, and leaving the apparatus free from the talking Wires of the trunk.

it may be stated here that each cord pair is equipped with a pair of relays EF -R? and a bank or" keys KK -K individual to that cord pair, but that the commutator shaft and its series of wheels is common to all cord pairs and connectors in the entire exchange.

lle rring now to Fiq. 3, I will briefly The switch, shown only in diagram, but in so far mechanics features are concerned it to type shownin the following pat- Keith and Erickson, 815,176, and Slo jii, granted March 13, 1906. The cir enits flemploy in the present case are-err tire y. dill'ere'nt from those of these patents, huh I to mechanical structure is so far the same that I employ a Vertical spindle, s, which carries wipers, s, to cooperate with the linc-termgigels, 5 (see Fig. 1) or linemultiples, in the switch-banks; the switch spindle is set up step Joy step by the vertical magnet, shand is rotated step by step by the rotary magnet, ,9, controlled respectively by the relays, It and R T here are supposed to be one hundred pairs of line-terminals in the switchbanks, and I do not require any eparable test terminals, since I test directly on the tip side of the line {or a ground. [he switch spindle controls a pair of springs, which it opens when it is down in its normal position of disuse. for restoring, purposes, will presently appear. a the ise magnet of the switch, which w en entr nced rein-ores the detent pawls thin the respective ratchets of the spindle, allowing the spindle to drop down and iii-tare hack tozero, fully described in the E32, cuts referred to. This release magnet is under the control of the relay, R. which in turn is controlled by he relays, It and IF. it is also under the control of the test relay,

descrihe the switch operation. S i

' it. il is a ringing-selectorcontrol relay,

A. is a trunk cut-oil relay and R is a ringing relay controlled by the commutator, X. which is common to the entire exchange, and is mounted upon the shaft oarrying the wheels Q", Q, Q..etc. of Fig. i. or i, mounted to rerohe in synchronism with that shaft and its coimnutator wheels. it

transmission.

is a slow acting relay, preferably a solenoid, which connects the test relay, l, at the moment oi" effecting connection, as controlled by the fir-stringing impulse, and at the same time opens the generator circuit, 41, while the proper current is being selected. l to. 11, inclusive, are selective relays for enabling one or the other of the ringing generators, G, G, G and G", to be connected onto the ringing contacts of the ringing relay, ll, the particular generator being determined by the number of impulses received through the ringing-selector control relay, It", which operates the relays, il R 1"", It, R R or as many of them as are desired, in succession, each or them locking as it operates.

The operation of this trunk scheme is as follows: In selecting the number we have.

assumed 4432 3; the trunk itself corresponds to the number 44, so we have first three ba'ttery impulses coming over the wire 23, to the relay, it, followed by two ground impulses over the wire "24 to the relay R and then three battery impulses again over the Wire 23 to the relay, ll. The first three battery impulses coming over tlie'wire 23 cause the relay R to pull up three times, each time closing the following circuit: B, 42, 43, 44, 5' 45, 46, 4'7, and ground to battery. The Vertical magnet, 8, steps the spindle, e, or the switch up three steps, so that the wipers, 5, stand opposite the third row of contacts. Two ground impulses then come over wire 2-1, aiiiecting the relay, It, which pulls up twice, the first time closing the following circuit: 13, 42, 48, R", 49, g armature of R 5 to ground and'to battery. The relay, R, instantly pulls up, cutting oil the vertical magnet, a, and locking itself by the following path: B, 42, 48, R, 1"", 52, 50, 51 and ground back to battery. The vertical magnet, .3 istheret'ore cut oil for the rest of the The rotary magnet, .9 however, gets current each time the relay, R is energized. over the following" path: 13, 42,43, 44,82 53, 54, 55 and ground each to battery. The rotary nragnet, .9 turns the spindle, .9, two steps, so that the wipers rest on the second pair of contacts in the third row, or No. 32. Three battery imp" is now come over the'wire causing the relay, again to pull up three times. Each time'it closesthe following local circuit: B, 42, 56, R 57, .46, .47, and ground back to battery. As a branch of this same circuit, the wire 58 comes in from battery wire 42 through the solenoid R and goes to 57, 46, 47 and ground.

it this point in the development or the connection immediately following the clo- Al and closing the switch 62 whereby a 3O conductor 41 to the right hand switch of winding of relay R and ground; however,

' ing conductor to left-hancl-armature of R tracts its core opening the wires 40- test circuit is formed through elements B, 42, 62, It, 63 to upper s, which at this moment is resting in contact with the line se lected through the agency of vertical and rotary magnets s 8. 1f the line be busy then a circuit will exist from upper wiper s to the tip of the plug and through the relay R to ground in case the line tested has called, or to another wiper s and thence through a trunking equipment following the path through contact .of R contact of R conductor 23 and winding of R to ground if that line has been called; in either case the test relay R will be energized and in turn will energize the release magnet 8 I f, however, the selected line with which the test wiper rests in contact is not busy no circuit will exist from that test wiper to ground and the test relay R will not be energized; a branch path for the conductor 63 exists through the talking conductor of the trunk to the left hand contact of relay R and thence to an armature contact of relay R where it terminates open, but subsequent to the energization of relay R as about to be described, this branch path passes to the inner contact of the left-hand armature of that relay and thence over the the solenoid R which during the test period is open, and thus test relay R has its circuit open at all points and the design of the device as a whole is that no energization of that relay may result when the line selected is in a condition of disuse and subject to use in the connection now being es tablished. (2) The relay R is energized over the path B, 42, 56, R 57 46, 47 and ground. By the closure of the left-hand armature of relay R circuit is formed through elements B, 42, 56, 59, armature of t, 60,,winding of R 61, switch's and ground, energizing relay R which locks itself energized over the circuit B, 42, 43, armature and inner contact of relay R winding of relay R 61, s and ground. This energization of trunk-connecting relay R connects the conductors 23-24 of the trunk through to the outer contacts of the ringing relay R and through to the wipers s. This furnishes a path through test re lay R as follows :-B, 42, 62, R 63, talkbaek contact and talking conductor to armature of energized relay R conductor 23,

this circuit is adapted to be opened by the attraction of the armatures of r'elayB and it is the function of the connector switch that the opening of this circuit at R shall succeed its closing at R by a time limit so small that restoration of the connector selection impulses and switch is not permitted. It will be noted of the test relay R from the wiper s to ground through the relay R of the same connector is at best only momentarily closed, this closure being'du'ring the instant after the operation of relay R and before the operation of R it follows that the series of necessarily consecutive operations just traced with respect to the release magnet can not occur during this very short inter-- val, and therefore no false test resulting ina consequent improper release occurs.

The commutator X, as has been men-.

tioned, is carried'upon the shaft which carries the number wheels and commutator devices Q,,Q,Q,Qj-,etc.,and the commutator X is adjusted angularly with respect to thosewheels so'that the conducting portion of X is in electrical connection with its brush at theotime that the energization of the relay R occurs.

It is seen that by the closing of contacts of R by which current flow through relay R was permitted, current was simultaneously provided for through path 13,42,- ing of R, contact and armature r, 68,50,

1', 51 and ground. Thus current begins to flow through the winding of relay R at the same instant that current begins to flow through the winding of relay It, and, assuming equal speed in the operation of armatures, relay R will have moved its armature and will have broken its back contact, thereby cutting oif current from relay R, in ample time to prevent the restoration of the switch S by operation of release magnet 8 the break at the armature of It probably occurring in time to prevent any contact whatever at, the armature of relay R.

I Thus test condition is maintained with the test wiper s lsolated from the winding-of relay R by the break at the armature of relay R and the design and adjustment of the commutator X shall be such that'the relay 1% maximum period occupied by generator the circuit of the test relay It by the opening of the switch 62 upon release of themmature of the solenoid R The armature of the solenoid R is sluggish and does not open the switch 62 between the generator;

selection impulses, so that the test circuithere described is maintained continuously during the periodof generator-selection.

X, wind is held energized throughout the until the opening of A various parts of apparatus in v dered, we will tollow the action o i apparatus in r spouse to the generaiousclechon impulses. In the inthe relay it" successively three times, which in turn acts over the path 5, ill. 57.1 etc.,

to ogerate the arinatures of relay 1% in succession three times; the armature 1' through its front and hack contacts eii'ccts the selection of the desired ringing generator as follows: Upon attraction of 9' by the first generator selection impulse, it makes electrical connection with i-ts inner contact, but inasmuch as the wire G1; is open at the armature of relay R no complete circuit is closed.

Upon therelease or" the armature 1" at cessation of the first generator-selection inipulse, circuitis closed through elements B, 12, e3, contactof R 60, 1' contact of R winding of R and ground. energizing relay which locks over the circuit l3, l2, 4E3, contact of R 60, 39,- arinature and contact of R finding of R and ground. If out one generator-selection ii'nuulse were received, the generator would remain in connection with conductor e ready for conneition through conductor 41 to the contact of the ringing relay 3 At the beginning of the second generator-selection impulse, relay R is ene gized and armature r is attracted, closing circuit through elements B, l2, contact of R 6G, a, 6%, closed contact of lower armature of relay R hack contact of unenergizecl relay winding of n relay R and ground, energizing relay R which their loc is over th circuit B, -12, l3, contact of l t- 60, 69, armature contact and winding of R Upon the cessation of the second geiierator-selection impulse. the armature T released, closing circuit over l3, l2, 43, contact of ll", 60, r, 65, closed contact or lower :rn'iature off energized relay R hack contact of lower armature of unenergized relay winding of relay l and grzumd, 2' Zing relay 1 which then locks its-c t through -ts own contact hy current received ov cr ccunluctor 69 to ground 's i and n it no on impulses were reas in the ca e o more generator-s;

wired. the cticct of the two impulses thus far followed would he to leave generator G connected to conductor l0 through contact of energized rel-1y ii, that being the proper gen rater for glng the second station on a party line.

At the beginning of the third .and las i gelieratonsclcctimi impulse, the armature r s gain attracted. closing circuit over clev 111 contact of R (30. r. (34. 'i ol? c11 3!"-i7.!3l,lciuy ii, closed winding of relay R and ground, energizing relay i i, which then locks itself by current through its own contact and winding over conductor so to ground. Upon the cessation of the third and last generator-selection impulse, the armature r is released, closing circuit through elements 15, 4:2, 43, contact of H 50, "r 35, closed inner contac s ot' energized relays R and it", closed outer contact of unenergized relay R winding of relay R and ground, energizing relay R which then locks itself by currentthrough its own armature contact and wind ing from conductor 69 to ground. This leaves relays R and R energized and leaves relay B unenergized, thus effecting the connection of 'enerator Gr to the conduct-or l0, and as the generator-selection impulses now cease, solenoid R releases its armature, opening the circuit of the test relay B and closing the circuit between conductors O-ll, thus connecting the selected generator G over conductor %l to the inner contact of the left hand armature of ringing relay R and thus through the upper wiper s and to the line conductor of the selected line to ring the third station upon the party line selected. The ringing will continue until the insulated portion of the commutator X passes under the brush of that commutator when the circuit of the winding of relay 1 will he interrupted and by release of that relays armature the circuit from the wipers s will be removed from the generator and carried to relays R and K respectively. The line selected will be subjected alternately to periods of ringingwhen the relay R is energized and to periods of non-ring ing when the relay It is deenergized. Upon the answering of the called. sub-station, or of any sub-station upon that party line, during a period of non-ringing, current innnediately will flow through elements B, 42, winding of R 24 lower 8, line conductor, substation bridge, return line conductor, upper s, 23,-winding of ll and earth, energizing R and attracting its armatures.

By the operation of the left hand armature of ll circuit is closed through elements l3. l9, lefthand armature and inner contact of l winding of R 54, contact and left hand armature of R and ground, energizing R which then locks tor the circuit B, Q, right hand armature and contact of R to winding of R, J-l, contact and armature of R and ground. By cnergization of relay R ground talicn oil of wire 50 sothat ringing relay ll may not again' he einn-gized. Also the energization and locking of R the. relay R is released and remains released throughout the remainder of the connection. This is the condition of coiriersation and continues until the hauging 11 of the telephone and the breaking of the substation.hridge upon the called line.

&

. Upon the hanging up of the telephone and the breaking of the substation bridge upon the called line, disconnection of the switch S is effected as follows: Circuit is interrupteiil over the return wire of the line and through relay "R to ground, releasing the armatures of relay R, but current con tinue through elements B, 42, winding of 11 ,24, lowerwiper s, and thesleeve side of the connected line andthe winding of its cut-ofi relay M to ground, maintaining the encrgization of the relay R By the release of the left hand armature of relay R a release relay circuit is established through elements B, 42, left hand armature and outer contact of dcenergized relay R, winding of release relay R inner contact and armature 1 of relay R 51 and ground, energizing release relay, R which, by closing its contact, energizes release magnet s, which efiects immediate restoration of all parts of the switch S to the normal position of dis- A consideration of test conditions during the process of the connection is desirable. lVhen the test wiper or upper wiper 8 connects with the test conductor of the selected line, no action is taken either to test for busy or to place a busy test upon the line until the wheels Q, Q Q etc., have in due course of progress begun to send the generator-selection impulses; at this time, by the action of the solenoid R the selected line is tested for busy condition, the testing for busy icing continued throughout the recei pt of the generator-selection impulses and the line being left unguarded against connection by other connectors; at the close of the generator-selection impulses the test relay is taken'oit and the ringing generator is substituted. 1 From this time a busy test guard condition is placed upon the test conductor of the selected line being alternately the potential of the selected ringing generator when the relay R is energized, which is sul'licient to energize any relay R which may test the line during the interval of ringing, and between the intervals of ringing the busy test consists of the ground circuit through the relay R. If the line thus connected with be tested for busyby some other connector attemptin a connection with it and during the 1nter$al of denergization of ringing relay R, a current will flow from the connector then testing to the test conductor of the line, thence through the test wiper of the connector of Fig. 3 holding the line, and through back contact of relay R, front contact of R 23, and winding of It to ground. This current will be of sufficient strength to energize the test relay R of the distant connector attempting to ,take th e line being held, and this will effect disconnection of that connector butit will not be of sufiicient strength to energize the relay I have thus described and stated the operation of one form of my invention. Many changes can be made therein without departing from the spirit thereof. In a prior application I have shown the same arrange ment as in Fig. 2, hereof, and also a number of other arrangements of the sender circuits,-

any one of which could be substituted herein.

It will be observed that the circuit during conversation is the same as the standard manual talking circuit, having a single pair of condensers, C, and the main battery B bridged across through a pair'of relays.

Havingthus described my invention what I claimis1- 1. In a telephone exchange system a plurality of subscribers lines having answering terminals and multiple 'or connective termina-ls, signal devices associated with the an swering terminals, automatic connector switches containing multiple terminals, an operators connectivecircui t adapted to connect the answering terminal of a calling line with a connector switch containing the multiple-terminals of the line wanted, and looking keys associated with the connective circuit adapted to be set by the operator for the number of the line wanted, and a mul-, tiple selection-impulse generator associated with said keys and operating through said keys to furnish selective impulses for selecting and connecting with a desired line.

2. In a telephone exchange system a plurality of subscribers lines, answering and multiple or connective-terminals for each line, automatic switches containing the multiple or connective-terminals, means controlled by an operator to connect a calling line with a given connector switch, a multiple signal sender, locking keys for select-- ing desired combinations of signals from said signal sender, and further means controlled by the. operatorto connect said keys and signal sender to the connector switch to operate said switch selectively, together with means whereby the subscriber may signal the operator when the conversation is finished.

3. In a telephone exchange system a plu-.

rality of subscribers lines, an answering switchboard and one or more automatic switches auxiliary thereto, answering terminals for the lines, loch ted on the switchboard,

multiple or connecting terminals for the lines located in the automatic switch-banks, automatic switch-terminals located on the switchboard, means whereby the operator may connect the same with the answeringterminal of a calling line when requ1red,a-

nlultiple power-driven signal transmitting each side of these condensers i Lit- 144 device, a plurality Gf5$t8 oi impulse select ing locking buttons whereby the operator by locking one button from each bank may so modify the signal transmitting device in toto as to cause a plurality of signals to be sent successively as required for the selection of a predetermined desired line, and means controlled by the operator to apply the same to an automatic switch'in order to completea connection manually initiated.

a. In a telephone exchange system a plurality or subscribers lines, an operators manual connective apparatus with auxiliary automatic switching apparatus, means whereby connection with calling subscriber is manually effected, the number wanted communicated to the operator, and a series of rows of locking keys adapted to be set to the desired line and station number and controlled by the operator to prepare said number for the auxiliary switches, together with automatic means comprising a plurality of independently and diii'erently characterized electrical control circuits for con trolling a switch in accordance with the number set, and means associated with the switches to automatically signal a called line when selected.

5. In a. telephone exchange system, a plurality of line circuits, means manually controlled by an operator for initiating a connection in answer to a call, acontrolling device, cc-sisting of a continuously revolving commutator device and a plurality of rows of locking number keys adaptedto be set in accordance with the number wanted, and automatic'means brought into operation by said. controlling device and actuated in accordance with the number set to complete the connection.

6. In a telephone exchange system a plurality' of line'eircuits, and means for interconnecting the same comprising the following instrumentalities: manual initiating or answering terminals, a number setting device, said number setting device consisting of a plurality of continuously revolving commutators and locking number keys, automatic switches controlled by said number setting device and acting in conjunction With the manual initiating apparatus to complete any desired connection, and automatic. means for ringing the called sub scriber.

' 7. In a telephone exchange system a plurality of line-circuits and means for interconnecting the same comprising the following instrumentalities: manual initiating or answering terminals, a number setting de vice, consisting of a constantly driven impulse sender and a set of locking impulseselecting number keys, automatic switches controlled by said number setting device and acting in conjunction with the manual initiating apparatus to complete any desired connection, and automa e means for ringing called subscriber, sa cl means being brought into action upon the completion of the connection by the automatic switch.

8. in a telep ions exchange system a plurality of line-circuits, and means for inte connecting the same comprising the following instrumentalities: manual initiating or answering terminals, a number setting dew vice, consisting of a constantly driven impulse sender and a set oi? ng impulsesclecting number is ys, an atic switches controlled by said ninnber st device and acting in conjunction with itiating apparatus to complete desired connection, and automatic means for ringthe called subscrib r, said means being brought into action upon the completion of the connection by the automatic switch and automatically rendered inoperative when the called subscriber answers.

9. In a telephone exchange system a plurality of subscribers lines, a manual switchboard containing answering terminals for said lines and call signals associated therewith, auxiliary automatic switches containing multiple or connecting terminals of said lines and having trunks terminating on said switchboard, with means whereby an operator may connect a switch-trunk with a calling line terminal, a signal controlling device on said switchboard adapted to be set by the operator for any desired number, a power driven impulse transmitter having definite signal periods, means for bringing said transmitter into operative connection with a selected switch-trunk at the beginning of a signal period to transmit impulses so as to work the automatic sivitch in accordance with the number set by the operator, and means to cut oil said impulse transmitter at the termination of the signal period.

10. In a telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, trunks extending to said automatic switches, manual means for connecting a calling line to one of said trunks, and an imlune.

pulse sending device eoinprisin a key board associated with each trunk together Wlth" automatic means to determine the connection and disconnection of said key board from the trunk for controlling the movements of the automatic switch of said trunk, to connect the trunk to the terminals of a desired line.

ll. In a telephone system, the combination of subscriber's lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, trunks to said automatic switches, manual means torcmnecting a calling line to one of said'trnnks, and a constantly driven signal sending device with looking the manual insignalselccting keys for controlling the movements of the automatic switch of said trunk throughout a plurality of successive directory digits to connect the trunk to the terminals of a desired line.

1'2. In a telephone system, the combination of subscribers lines, a calling jack and signal for each of said lines, automatic connector switches in which multiples of said lines appear, trunks to said automatic switches, manual means for connecting a calling line to one of said trunks, and a constantly driven multiple-signal-sending device for controlling the movements-of the automatic switch associated with said trunk to connect said trunk to the terminals of a desired line. 4

13. In telephone system, the combination of subscribers lines, a calling jack and signal for each of said lines, automatic connector switches in which multiples of said lines appear, trunks to said automatic switches, manual means for connecting a callin line through one of said trunks to one 0 said automatic switches, and a constantly driven multiple-signal-sending device with locking selecting number keys for controlling the movements of said automatic switch throughout a plurality of successive directory digits to connect its trunk to the terminals of a desired line.

14. In a telephone system, the combination of subscribers lines, a calling ack and signal for each of said lines, automatic connector switches in which multiples of said lines appear, trunks to said automatic switches, cord pairs for connecting a callj ing line with a trunk to one of said automatic switches, aconstantly dr ven signalsending device, and locking signal-selecting keys associated with said cord pairs for controlling the movements of said automatic switch to connect its trunk to the terminals of a desired line.

15. In a telephone system, the combination of subscribers lines, a calling jack and signal for each of said lines, automatic connector switches in which multiples of said lines appear, trunks to said automatic switches, a constantly driven multiple-signal-sending deviw, cord pairs for connecting a calling line to a trunk to an automatic switch, and sets of locking signal-selecting keys for each of said cord pairs whereby said automatic switch may be controlled throughout a plurality of successive directory digits to connect its trunk to the terminals of a desired line.

16. In a telephone exchange system, a plurality of subscribers lines; an operators manual connective apparatus with auxiliary automatic switching apparatus, said auxiliary automatic switching apparatus being divided into groups corresponding to groups of subscribers lines; means. whereby connection with a calling subscriber is manually effected and the number wanted communicated to the operator; means whereby the operator manually selects the group of automatic switching apparatus corresponding to' the number of the subscriber wanted; a'mechanical number-recording device whereon' the operator may record the digits of the number of the line desired supplemental to the directory digits provided for by proper selection switches; automatic means whereby the mechanically recorded directory number is translated into correspondingcontrolling impulses whereby the selected automatic switch is controlled to complete the 'connec-.

tion of the calling telephone line with the of the groups .of automatic between a calling line arid said automatic switching apparatus; a system of continuously revolving commutators producing in each revolution a complete cycle of selective impulses and locking keys adapted to ex- 'cerpt from any cycle the specific impulses required for a specific selection; and auto- .matic means for applying the excerpted impulses to the connected .automatic switch for the selection of the desired line, substantially as described. I Y

18. In a telephone exchange system,.a plurality of subscribers lines; an automatic switching apparatus; manual connective apparatus; whereby connection may be made between a calling line and said automatic switching apparatus; a system of continuously revolving commutators producing in each revolution a complete cycle of selective impulses and locking keys adapted to excerpt from any cycle the specific impulses required for a specific selection; automatic means for applying the excerpted impulses to the connected automatic switch for the selection of the desired .line; and further meansfor ringing selectively a station upon the selected line, substanti lly as described.

19. In a telephone exchange system, a plurality of subscribers lines; nector switches; manual switching apparatus for connecting a calling line to a connector switch; a mechanical number-recording de-.

vice; a constantly driven signal-sending device a'lapted to send multiple, signals in repeated cycles; and means whereby said signal-sending device may be connected to the automatic switch at the beginning of a cycle, may be permitted to send signals in accordance with the number recorded upon the number-recording device.

and may be disconautomatie connested from said automatic switch at the end of the cycle, substantially as described.

20. In a telephone exchange system, a plurality of subscribers lines; automatic connecter switches; manual switching apparitus 'forconnecting a calling line to a connector switch; a mechanical number'recording device; a constantly driven signal-sending device adapted to send multiple signals in repeated cycles; and automatic means whereby si nal-sending device may be connected to t e automatic switch at the beginof cycle, may be'permitted to send n accordance with the number revpon the number-recording device, i maybe disconnected from said autotic switch at the end of the cycle, substantially as described.

21. In a telephone exchange system, a pluof line circuits, automatic switching ratus for interconnecting the same, manual means for initiating a connection, means controlled by an operator through the automatic switches to complete it, and means controlled by the called subscriber for discorm'ection, substantially as described.

22. In a telephone system, the combination of subscribers lines, an answering jack and a calling signal for each of said lines, automatic connector switches in which multiples of said lines appear, trunks from a manual position to said automatic switches, cord pairs adapted to connect with said trunks, and a constantly-driven signal sending device with keys and locking signal selecting circuits for controlling the movements of an automatic switch to connect its trunk to a desired line, substantially as de-' scribed.

23. In a telephone system, the combination of subscribers lines, circuits and equip-- ment manually operated for answering said lines, automatic connector switches in which multiples of said lines appear, trunks from the manual answering position to said automatic switches, and a constantly drivensignal sending device, with signal selecting keys and locking circuits associated-with said manual answering equipment and adapted to control the selector switch of a connected trunk to connect its trunk with a desired line, substantially as described.

In a telephone system, the combinat subscribers lines terminating in an jacks; automatic connector switches n nhich multiples of said lines appear; ranks connecting said automatic v connector st itclies to jacks adjacent to the' answering jacks of said lines; cord pairsiadapted to T name Q he jacks and trunk-jacks, and a Cons driven signal sendn idevice with ny-m/ selecting number keys for controlling the move ic Q of sa d automatic switches to meet the Lrun the terminals of de vily s described.

red lines, substa:

25. In a telephone system, the combination of subscribers lines terminating in 'answering acks; automatic connector switches in which multiples of said lines appear; trunks connecting said connectorswitches to jacks adjacent to the jacks ofsaid lines; cord pairs adapted to connect line jacks and trunk jacks; a constantly driven signalsending device; and sets of locking signah selecting keys associated with each cordpair for selecting from said signal-sending device desired signal impulses for controlling the connector switch of a selected and connected trunk to connect its trunk with the terminals of a desired line, substantially as described.

26. In a telephone system, the combination of subscribers lines terminating in answering jack; automatic connector switches in which multiples of said lines appear; trunks connecting said automatic switches to jacks adjacent to the answering jacks of said lines; cordpairs adapted to connect line jacks and trunk jacks; a constantly driven signal-sending device; and sets of signalselecting keys with looking circuits and associated with each cord pair for selecting from said signal-sending device desired signal impulses for controlling the connector switch of a selected and connected trunk to connect its trunk with the terminals of a desired line; substantially as described.

27.'In a telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, manual means for connecting a'calling and a constantly driven signal-sending device with selecting number keys for controlling the movements of said automatic switch throughout a plurality of successive direc tory digits to connect the manually connected calling line to the terminals of a desired line.

28. In a telephone system, the combination of subscribers ines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, manual means for connecting a calling line to one of said'automatic switches, and a multiple signal sending device with selecting number keys for controlling the movements of said automatic switch throughout a plurality of successive directory digits to connect the manually connected calling line to the terminals of a. desired line.

29. In a telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automaticgconnector. switches in which multiples of said lines appear, manual means for connecting a callin line to one of said automatic switches, an a constantly drive; multiple signal line to one of said automatic switches,

- constantly driven signal sending device with selecting number devices for controlling the movements of said automatic switch to connect the manually connected calling line with the terminals of a desired line.

81. In a telephone system, the combina tion of subscribers lines, calling jacks and. signals for'said lines, automatic connector switches in which multiples of said lines appear, manual means for connecting a calling line to one of said automatic switches, and a multiple signal sending device with looking selectingnumber keys for controlling the movements of said automatic switch to connect the manually connected calling line v with the terminals of a desired line.

32. In a telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines ap pear, manual means for connecting a calling ine to one of said automatic switches, and a multiple signal sending device with selecting number devices for controlling the movements of said automatic switch to connect the manually connected calling line with the terminals of a desired line.

33. In a telephone. system, -the combination of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, manual means for connecting a calling line to one of said automatic switches, and a constantly driven multiple signal sending device with looking selecting number keys for controlling the movements of said automatic switch throughout a plurality of successive directory digits to connect the manu -ally connected calling line with the ter minals of a desired line.

34. In a telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiple of said lines appear, manual means for connecting a callmg line to one of said automaticswitches, and a constantly driven multiple signal sending device-with selecting number devices for controlling the movements of said automatic switch throughout'a plurality of successive directory dig1ts to connect the manually connected calling line to, the terminals of a desired line.

35. In a telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, manual means for connecting a calling line to one of said automatic switches, and a constantly driven signal-sending device with looking selecting number devices for con- -'swi tch throughout a plurality of successive directory digits to connect the manually condesired line.

tion of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, manual means for connecting a calling line to one of said automatic switches, and a multiple signal sending device with locking selecting numberdevices for controlling the movements of said automatic. switch throughout a plurality of successive directory digits to, connect the manually con-' nected calling line to the terminals of a desired line. .1 37. Ina telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automatic connector line to oneof said automatic switches, and a constantly driven multiple signal sending device with looking signal selecting devices for controlling the movements of said automaticswitch throughout a plurality-of successive directory digits to connect the call ing line with the terminals of a desired line.

38. In a telephone system, the combina tion of subscribers line's, calling jacks and switches in which multiples of said lines appear, cord pairs for connecting a calling line with one of said automatic connector switches, a constantly driven signal-sending with said cord pairs for controlling the movements of said automatic switch to condesired line.

39. In a telephone system, the combination of si'ibscribcrs lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, cord pairs for connecting a calling line with one of said automatic connector switches, a constantly driven signal-sending device, and locking signal-selecting keys associated with said cord pairs for controlling the movements of said automatic switch to connect the calling line to the terminals of a desired line.

tion of subscribers lines, calling jacks and ;s1gna1s for said lines, automat c connector nected calling line with the terminals of a 36. In a telephone system, the combinaswitche in which multiples of said lines appear, manual means for connecting a calling device, and signal selecting keys associated,

nect the calling line to the terminals of a;

trolling the movements of said automatic I signals for said lines, automatic connector t 40. In a telephone system, the 'combina- I switches in which multiples of said lines appear, cord pairs for coi'inecting a calling line with one of said automatic connector switches, a constantly driven signal-sending device, and signal-selecting devices associated with said cord pairs for controlling the movements of said automatic switch to connect'the calling line to the terminals of a desired line.

ll. In a telephone system, the combination of subscribers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appear, cord pairs for connecting a calling line with one of said automatic connector switches; a signal-sending device, and individually operable independently characterized interlocking sigginil-selecting devices associated with said cord pairs for controlling the movements of said automatic switch to connect the calling line to the terminals oi a desired line.

42. in a telephone system. the combination of suhsci-iliers lines, calling jacks and signals for said lines, automatic connector switches in which multiples of said lines appea r, co rd pairs for connecting a calling line connectorv with one 0% said automatic switches, a constantly driven signal-sending device, and loclring signahselecting devices associated with said cord pairs for controlling the movements of said automatic switch to connect. the calling line with the terminals ot' a desired line. Y

43. In a telephone system, the combination of subscribers lines, a calling jack and signal for each of said lines, automatic eonncctor switches in which multiples of said lines appear, manual means for connecting a calling line to one of said automati switches, and a constantly driven signalsending device with locking signal-selecting keys for controlling the movements of said automatic switch to connect the calling line with which it is manually connected to the terminals of a desired line.

44. In a telephone system, an operators connecting devices, an impulse generating device delivering impulses of varying characteristics, bus Wires leading to said operas tors connecting devices, contact pairs associated with said bus-wires, auxiliary conductors extending from said generating device to said contact pairs. and keys for controlling the connection of said bus Wires to said auxiliary conductors.

4:5. In a telephone system, an operators connecting devices, an impulse generating device delivering impulses of varying characteristics, bus wires leading to said operators connecting devices, cont-act pairs associated with said bus-wires, auxiliary conduc tors extending from said generating device to said contact pairs, and locking keys for controlling the connection ofsaid lous wires to said auxiliary conductors.

46. In a telephone system, an operators connecting devices, an impulse generating device delivering impulses of varying char acteristics, bus wires leading to said operators connecting deyiccs, contact pairs asso ciated 'ith said busavires, auxiliary corductors extending from said generating decontrolling the connections of said bus Wires to said auxiliary conductors.

47. In a telephone system, an operators connecting devices, an impulse generating device delivering impulses of varying characteristics, has wires leading to said operator s connecting devices, contact pairs associated with said has-wires. auxiliary conductors extending from said generating device to said contact pairs, and locking devices for controlling the connection of said has wires to said auxiliary conductors.

48. In a telephone system, an operators connecting devices, an in pulse generating device delivering impulses of varying characteristics, bus wires leading to said operators connecting devices, contact pairs associated with said bus-wires, auxiliary conductors extending from said generating device to said contact pairs, and signal-selecting keys manually controlled by the operator for controlling the connection of said bus Wire to selected ones of said auxiliary conductors. 49. In a telephone system, the combination of suhscribers lines terminating in answering jacks, automatic connector switches in which multiples of said lines appear, trunks connecting said automatic switches to jacks adjacent to the answering jacks of said lines; cord pairs adapted to connect line jacks and trunk jacks. a power driven signal sending device, and sets of individually operable independently characterized signal selecting keys with locldngcircuits through which they may be con nected with each cord pair for selecting 1 from said signal sending device desired sig nal impulses for controlling the connector switch of a selected and connected trunk to EDWARD E. CLEMENT.

Witnesses:

lanes l. MARK, E. Eigioixsiox, Jr.

vice to said contact pairs, and devices for 

